This section is from the book "A Text Book Of Materia Medica, Being An Account Of The More Important Crude Drugs Of Vegetable And Animal Origin", by Henry G. Greenish. Also available from Amazon: A Text Book of Materia Medica : Being an Account of the More Important Crude Drugs of Vegetable and Animal Origin.
Indian or Tinnevelly senna consists of the leaflets of Cassia angustifolia, Vahl, which is indigenous to southern Arabia, but is cultivated largely in southern India, especially in the district of Tinnevelly, in the extreme south-east. Here the plant attains an unusual luxuriance, and produces larger leaves than the Arabian wild plant. They are carefully collected, dried, pressed into bales, and exported from Tuticorin.
Tinnevelly senna is usually free from admixture either of foreign leaves or even of stalks and fruits. The leaves resemble Alexandrian senna rather closely, but are generally of a yellowish green rather than greyish green colour, a difference more noticeable in bulk than in single leaves. They attain a larger size than the Alexandrian, varying usually from 2 5 to 5 cm. in length. They differ also in being more uniformly lanceolate in shape, less conspicuously asymmetrical and less pubescent. They are somewhat firmer in texture than the Alexandrian, and are consequently less broken when they arrive, and, being exported in compressed bales, are usually flatter. There is also a slight but perceptible difference in the odour of the two varieties. The student should carefully compare these two varieties of senna. It is, however, quite possible to select from the two varieties exceptional leaves that are indistinguishable from one another. The student must be guided by the characters of the majority.
Fig. 24. - Tinnevelly Senna leaves. Natural size.
The constituents of Tinnevelly senna are identical with those of Alexandrian senna. Either variety may be used in making the official preparations of senna.